Furnace-draft heater.



No. 687,565. Patented Nov. 26, I90l. J. B. HUUSTUN.

FURNACE DRAFT HEATER.

(Application filed Mar. 27, 1901.)

(H Model.)-

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UNITED STATES PATENT OFFICE.

JOHN BROADFOOT HOUSTON, OF VANCOUVER, CANADA.

FURNACE-DRAFT HEATER.

SPECIFICATION formingpart of Letters Patent NO. 687,565 dated. November 26, 1901.

Application filed March 27, 1901. Serial No. 53,118. (No model.)

To aZZ whom it may concern-.-

Be it known that I, JOHN BROADFOOT Hons TON, a citizen of the Dominion of Canada, residing at Vancouver, in the Province of British Columbia, Canada, have invented a new and useful Furnace-Draft Heater,of which the following is a specification.

My invention consists of improvements in that form of heat-economizer wherein the uptake conveying the waste gases from the boiler-tubes to the smoke-stack is surrounded with a double casing and has a group of tubes passing horizontally from side to side thereof; and my object has been to direct the air for combustion through the casing and tubes in as simple a manner as possible, so as to render the system applicable to small boilers having perhaps only one furnace, though I do not desire to limit its use to such. To obtain the fullest efficiency, I have also endeavored to provide a means for keeping the outside of theeconomizer-tubes free from soot deposits, which is a very essential requirement.

The following drawings illustrate the application of my system to a small boiler having a single furnace and return-tubes.

Figure 1 is a vertical section on the line a a in Fig. 2. Fig. 2 is a vertical section on the linebbin Fig. 1, and Fig. 3 is a horizontal section on the line 0 c in Fig. 2.

In the drawings, B represents theboiler end; F, the furnace; T, the return-tubes, and

U the uptake, through which the waste gases from the furnace pass to the smoke-stack S.

2 and 3 are the Walls of the air-jacket,which surrounds the uptake and is joined below to the furnace-front, the lower part forming a reservoir R, from which the air for combustion is admitted to the furnace.

1 represents the tubes connecting the two side jackets across the uptake and exposed to the heat of the furnacegases.

At one side of the uptake-jacket I provide partitions 31 31, which cut off that side from direct communication with the incoming air entering the jacket at the inlet 4. At the opposite side I provide a division 32 below the level of the lower tube, which prevents the air passing to the reservoir direct and compels it to first pass through the tubes 1. The

arrows clearly indicate the direction of the air-current, which, entering at 4, passes directly across tothe opposite side by the front and back jackets, thence through the tubes 1, and down to the reservoir Rto be regulated in its admission to the furnace by a suitable means.

To clear away the soot and furnace-dust which Will deposit on the surfaces of the tubes 1 and walls 2 of the uptake, Iprovide a vertical perforated steann-pipe 40 just inside the inner wall 2 and about the middle of the front. This pipe 40 is closed at the upper end and at the lower end passes through the sloping frame between the smoke-box doors, through a small casting 41, and is connected to the external steam-pipe 42 in the gland 43. A handle 44 enables the internal steam -pipe 40 to be rotated through asufticient arc, and, the perforations 45 being pitched to correspond with the spaces between the tubes 1, on steam being admitted into the pipe 40 it issues in jets through the perforations 45 and efiiciently cleans off all adherent soot, &c., which is carried up the smoke-stack by the draft.

I am aware that prior to my invention air for combustion has been heated by the waste gases in a similar manner and that steam-jets havebeen used to clear the interior surfaces of flues; but

What I claim-as new, and desire to be protected in by Letters Patent of the United States, is

1. In an economizer of the class described, partitions in the jacket air-spaces which will compel the incoming air for combustion to travel inone direction through the tubes and thereafter to descend to the reservoir adjacent to the furnace; a vertical steam-pipe in the uptake capable of rotation on its longitudinal axis; perforations in the steam-pipe adjacent to the spaces between the economizer-tnbes; a lever ex'terior to the uptake for partially rotating the vertical steam-pipe and means for admitting steam to within the pipe as desired, all substantiallyas specified.

2. In an economizer of the class described, in combination with a group of tubes passing horizontally across the uptake, a vertical steam-pipe within the uptake adjacent to such tubes and connected with an exterior steam-supply; perforations in the stearn pipe between each row of tubes; a lever fixed to the perforated pipe exterior to the uptake, and a gland connection which will permit the rotation of the perforated pipe, substantially i as and for the purposes described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN BROADFOOT HOUSTON.

\Vitnesses:

ROWLAND BRITIAIN, ELLICE WEBBER. 

